Electrolytic protection of metal surfaces



Feb. 27, 1945'. BR'OL'INSON 2,370,288

ELECTROLYTIC PROTECTION OF METAL SURFACES Filed Aug. 1, 1940 4 sSheets-Sheet 1 INVENTOR- figg/ ti Brlz'nsan ATTORNEY Feb. 27, 1945.- B,G. BROLINSON ELECTROLYTjEC PROTECTION OF METAL SURFACES Filed Aug. 1,1940 3 Sheets-Sheet 2 Feb. 27, 1945'. BRQLJNSON 2,370,288

ELECTROLYTIC PROTECTION OF-METAL SURFACES Filed Aug. 1, 1940 3Sheets-Shet s -INVENTC )R V fzBruimsw;

Patented Feb. 27, 1945 ELECTROLYTIC PROTECTION OF METAL SURFACES BengtG. Brolinson, New York, N. Y. Application August 1, 1940, Serial No.349,124 1 Claim. (Cl. 204-196) This invention relates to theelectrolytic protection of metals and more particularly to a system andapparatus for the electrolytic protection of containers, such as heatexchangers, conproposed to insert an anode in the liquid withinv thecontainer and to connect the surfaces to be protected as the cathode toa source of curret. In certain instances, however, it is inconvenient orimpracticable to insert anodes in the containers themselves. Such is thecase in certain types of heat exchangers or condensers wherein the spaceis not sufiicient to receive the necessary anode surfaces. Furthermore,the cost of inserting anodes in a plurality of containers may beprohibitive.

In order to effect the necessary protection in cases of this kind it hasbeen proposed to provide a separate anode chamber which is connected inthe fluid circuit so that fluid passes through the anode chamber on itsway to or from the container. The present invention relates particularlyto this type of equipment and has for an object to provide a system ofnovel and improved construction, which is simple and convenient toinstall and which is eflicient in ope,

eration.

Another object is to provide an anode cham- Another object is to providean anode chamber having novel and improved details of construction andfeatures of operation.

Another object is to provide a novel and improved anode support.

Still another object is to provide a novel and improved means forsupplying current to an anode in an elongated anode chamber.

A further object is to provide an anode chamber which is so constructedand arranged that the sediment or accumulations therein, may beperiodically removed so as to prevent clogging of the chamber orinterruption of the operation of the system.

Various other objects and advantages will be apparent as the nature ofthe invention is more fully disclosed.

Although the novel features which are believed to be characteristic of.this invention are pointed out more particularly in the claim appendedhereto, the invention itself may be betterunderstood by referring to thefollowing description, taken in connection with the accompanyingdrawings in which the specific embodiment thereof has been set forthwith illustration.

In the drawings: a

Fig, 1 is a top plan view of a bank of condensers having an. anodechamber embodying the present invention associated therewith;

Fig.2 is a side elevation thereof;

Fig. 3 is the vertical longitudinal section of the anode chamber takenalong the line 3-3 of Fig. 2;

Fig. 4 is an enlarged detailed view of a portion of the anode chambershowing the anode support and the lead-in means for connecting the anodeto an external circuit;

Fig. 5 is a transverse section taken on the line 5-5 of Fig. 4;

Fig. 6 is a side elevation, partly in section,-of an anode chambercontaining a solid anode;

Fig. '7 is an enlarged section taken on the line l-! of Fig. 6 showingthe construction of the current lead-in means;

Fig. 8 is a transverse section taken on the line 8-8 of Fig. 6 showingthe anode support; and

Fig. 9 is a side elevation showing a bank of condensers withintermediate electrode chambers arranged for the serial flow of thefluid therein.

Referring to the drawings more in detail the invention is applied to abank of containers, shown for convenience as condensers H), which areconnected by individual inlet pipes l2 having control valves l3 to aninlet header II to receive therefrom the fluid, which in the case ofcondensers may constitute cooling water. It is to beunderstood that thecondensers are also connected to a suitable outlet header, not shown.

The water is supplied from a main id to the inlet header l-I through avalve I 5. An anode chamber I6 is positioned parallel to the header Hand is connected at opposite ends to the ends of the header by elbows l1and I8 controlled by valves I9 and 20 respectively, the arrangementbeing such that with the valve 15 closed and the,

valves l9 and 20 open the water is supplied from the main 14 through theanodechamber l6 and thence to the header II and the condensers 10. Withthe valves l9 and 20 closed and with the valve l5 open, water issupplied from the. main I4 directly to the header H and thence to thecondensers ID, the anode chamber l5 being then cut out of service andrendered inactive. It is to be understood that the condensers It! may beof the tube and shell type or of any other standard construction havingmetal parts which are subject to corrosion, scaling and fouling.

The anode chamber it, as shown more in detail in Figs. 3 and 4,comprises a tube 2i having a cross section substantially greater'thanthat of'the main M and the header ii. The elbows l1 and it may beconnected to the opposite ends of the tube ill by means of flanges 23and Ed. The elbow ill may be provided with a drain-pipe 25 having avalve 25 therein which, when open, permits the sediment or othermaterials in the pipe 2! to be removed.

The anode chamber contains an anode which is shown as an anode tube 28,which may be closed I if desired, mounted concentric with the tube 2iand insulated therefrom, The anode tube 218 may be supported by spacedpairs of legs shown as insulators 3b (Figs. 3, 4 and 5) which may beattached to the anode tube by suitable means,

shown as bolts iii. The outer surface of the anode tube 28 may berecessed to receive the insulators The insulators may be provided withcaps 35 which may be formed with spherical tion only of the periphery ofthe tube so that I the anode tube 28 may be inserted with the legs 30out of alignment with the blocks iii. After insertion the tube 28 may berotated to bring the legs 29 into locking engagement with said blocks 4!for positioning and securing the anode as shown.

For making electrical connection to the anode tube 28 an ear may besecured thereto by suitable means such as by welding. A flexibleconnecting cable 46 maybe secured to the ear 45 by a bolt 41. v

The tube Zl-may-be provided with an opening 50 of suflicient size toafford access to the interior of the tube. The opening 50 may be closedby a cover plate 5| which may be secured Suitable gaskets and Gil bybolts 52 and may be provided with a sealing asket 53. The cover plate 5|carries a' lead-in assembly comprising a metallic sleeve 55 passingSuitable insulation 63 such as mica may be provided around the rod 62 toinsulate the same from the sleeve 55. The assembly may be secured bymeans of lock nuts 64. An insulating gasket may be inserted over thesleeve 55 toinsulate the lock nuts 64 and the rod 62 therefrom.

The flexible connecting cable-46 may be provided with a flat connector10 secured by means of a nut 68, to a threaded shank 59 formed on theblock 6|. The exposed parts of the cable 46, the block BI and the ear 45may be wrapped with insulation so as to completely seal the conductingparts from contact with the water in the tube 2|.

,legs 29 to permit inspection or adjustment thereof if desired, withoutdismantling the entire apparatus. The holes id may be closed by coversl6 secured by bolts ii.

For flushing out the anode chamber iii and removing deposits from theanode a set of nozzles $30, controlled by individual valves 82, isprovided. In the embodiment shown these nozzles 85 are arranged ingroups .of three peripherally spaced about the tube 2i near the ends ofthe anode tube 28 and directed towards the center of said tube. Thealigned nozzles sit at the two ends of the tube 211 may be connected topipes Si which are in turn connected to pipes 83 which are connected toa high pressure header til controlled by a valve 85 so that water underpressure may be supplied to said nozzles when desired. The nozzles mustbe arranged to provide a maximum clearance from the anode and may, ifdesired. be mounted in chambers raised above the surface of the tubes 25similar to the chamber formed by the T i i id to be described, or thenozzles may be made of non-metallic material.

In the operation of this device the valve 5 5, Fig. l, is normallyclosed, and the water is supplied to the condenser iii through theanodechamber i t. It is to be noted that the condensers are connectedtothe header ill in parallel and that the anode chamber i6 is connectedin series with the bank of condensers. Suitable electrical connectionsare made to the surfaces to be protected and to the'rod 62 supplyingcurrent to the anode 28, so that the anode is made positive and thesurfaces to be protected are made negative. The anode itself, however,corrodes and must be renewed or replaced periodically.

It has been found that after the system has been operated forasubstantial length of time the anode chamber l6 becomes clogged due tothe particles deposited from the anode and from the water itself and dueto the scale which is removed from the anode. cally cut out of servicefor cleaning by opening the valve I5 and closing the valves i9 and 20.The chamber may then be flushed out by opening the valves 85 and 82 andsupplying water to the nozzles 80. The material thus removed from theanode falls to the bottom of the anode chamber and may be flushed out ofthe drain pipe 25. If sufficient water is not received from the sprays80 for this purpose the valve 20 may be opened to supply water to thechamber to flush out the accumulated material; The system may also bereserve-flushed by opening the valve i9 and closing the valve 20 tosupply water through the elbow I! to the anode chamber.

When the anode 28 is to be removed the cover 5| may be removed to affordaccess to the cable 46 which may then be disconnected. The elbow l1 maythen be removed and the anode may be withdrawn axially. It is to benoted, however, that the anode must first be rotated to release thesupporting legs 29 from the blocks 4 l The cove: plates 16 may beremoved for purpose of inspection or repair of the blocks 4|. Theflushing out of the anode chamber and the inspection provided for by thevarious inspection ports permits the anode to be maintained incontinuous service without dismantling except when it is necessary toremove and renew the same.

In certain instances it may be desirable to use a solid .anode such as asolid carbon or graphite rod. This embodiment of the invention is shownThe chamber may be periodiin Figs. 6, '7 and 8 wherein the anode chamberI8 is similar to that above described. An anode rod 90 is provided,however, which in this embodiment is supported by legs 9| of suitableinsulating material having secured therein, threaded studs 92 which arealso secured in suitable tapped holes 93 in the anode rod 90. Suitablerecesses 94 are provided in the anode rod to receive the ends of thelegs 9|. The legs 9I are provided with caps 95, similar to the caps 35above described.

In this embodiment the lead-in means differs from that shown in Figs. 1to 5. As shown in detail in Fig. 7 the lead-in means comprises an insert96 of impervious material such as treated graphite which may be threadedinto a tapped recess in the side of the anode rod 90. A washer 91 may bepositioned beneath the insert 96 to facilitate assembly and removalthereof. A terminal stud 98 is threaded into the insert 96 and aninsulating sleeve 99 is threaded over the stud 98. The end of aninsulated, flexible conductor I is inserted in a recess in the pin 98and may be secured by a set screw IOI.

In order to make a water-tight seal so as to prevent moisture fromentering beneath the ends of the insulation of the conductor I00 apacking box is formed by the insulating sleeve 99 which is closed bymeans of a non-metallic gland I02, threaded in said sleeve. The sleeve99 may be seated on a sealing gasket I03.

The other end of the conductor I00 is connected to a rigid lead-incomprising a metal sleeve I I0 which passes through a cover II I mountedon a T Illa and secured by bolts lb. The T Illa provides clearance toobtain the length of insulator surface required to prevent surfacecreepage. The sleeve IIO may be secured in the cover III by nuts II2 andH3. "A gasket H4 and a washer II5 may be provided to eflect a watertightseal. An insulating sleeve IIB extendsinwardly from the sleeve II 0 andis securedby a current conducting rod I H which extends through thesleeve H0 and HE. A coating of insulating material II8, such as mica,surrounds the rod II1 to insulate the same from the sleeve H0. Thesleeve H6 is clamped between a threaded head I24 and the sleeve I I0 bymeans of a nut I threaded on the rod I I1. Sealing gaskets I2I and I22may be inserted over the ends of the sleeve I I6 and an insulatingwasher I23 may be disposed between the sleeve III] and the nut Aterminal stud I I9 may be threaded onto the end of the rod I IL The endof the conductor I00 is secured in the terminal stud I I9 by means of aset screw- I26. A packing box is formed by an insulating sleeve I27which is threaded onto the stud IIS, and a non-metallic gland I28. Aninsulating and sealing gasket I25 may be inserted between the head I24and the sleeve I21. All electrical conducting members are thus sealedfrom contact with the water within the tube 2 I. The flexibility of theconductor I00 permits expansion of the parts due to temperature changeswithout damaging the equipment.

The embodiment shown in Figs. 6, '7 and 8 provides for the use of asolid anode rod. This may be desirable in the case of graphite or carbonrods, which have the property of protecting the oathodic surfaceswithout discoloring the liquid or introducing any metal ions therein.

In the embodiment shown in Fig. 9 a plurality of containers I30 areconnected for the serial flow of water therethrough and a plurality ofanode chambers I3I are arranged intermediate .ers and anode chambers.

In this system the anode chambers are positioned adjacent the inlet toeach container so as to obtain the most eilicient action. The anodechambers are shown as graduated in size according to the temperature ofthe fluid in the various containers so as to take advantageof theincreased conductivity of the hotter fluid, by reason of which lessanode surface may be required. It is to be understood that the anodechambers I 3| are similar in construction to the anode chambers I6 abovementioned and may be bypassed when desired, consequently the detailsthereof have not been repeated.

In the system shown in Fig. l a single anode chamber is used to protectthe plurality of condensers. In the system shown in Fig. 9, a pluralityof anode chambers are used, one for each condenser or other element tobe protected. The particular system used will depend upon therequirements of each individual case and may differ according to themetals present, the nature and content of the cooling fluid and theconditions of operation.

Since the anode chamber is filled with Water or other conducting fluid,it is essential to completely insulate all conducting members. vIt isalso necessary to provide suificient flexibility to permit relativemovement between the anode and the anode chamber due to expansion orcontraction of the parts. In the embodiment of Figs. 1 to 5 this isaccomplished by connecting a flex-- ible cable between the anode and aninsulated lead-in which passes through the wall of the anode chamber. Inthe embodiment shown in Fig. 8, connection is made by means of aflexible insulated conductor. The joints between the conductor and thetwo terminal studs 98 and. i I9, however, are completely insulated andsealed by the stuffing boxes so as to prevent water from creeping insidethe insulating covering. This construction prevents the conductingmembers from corroding due to contact with the water.

It is to be noted that the lead-in of Fig; 4 may be completely assembledand tested in the factory. This eliminates the necessity for assembling'and testing the conductors in the field. Furthermore, the cable 46 maybe disconnected by the removal of the nut 68 without disassemblingthelead-in itself. This is an important feature from a commercialstandpoint inasmuch as it is more difiicult to obtain a permanentwater-tight assembly in field than in a factory where there are properfacilities for assembling and testing.

The invention has been described as applied and modifications may bemade therein as will be readily apparent to a person skilled in the art.The invention is only to be limited in accordance with the followingclaim.

What is claimed is:

A device for the electrolytic protection of metal surfaces in acontainer, comprising an anode chamber, an anode in said chamber, andlead-in means extending through said wall to make an electricalconnection with said anode, said lead-in means comprising a metallicsleeve extending through said wall and secured thereto, an insulatingsleeve extending inwardly from said first sleeve, a lead-in rodextending through said sleeves, insulating means surrounding said )15lead-in rod to insulate the same from said metallic sleeve, a terminalblock carried by said lead-in rod, means on said rod to clamp saidsleeves against said block, a terminal block mounted in said anode, saidterminal blocks having bores to receive the ends of a connecting cable,a flexible cable connected to both of said terminal blocks, said cablehaving an insulated covering, the ends of which are inserted in said it)bores and stufiing boxes associated with the bores of each of saidterminal blocks to seal the ends of said insulation from the surroundingmedium and prevent contact thereof with said cable.

BENGT G. BROMNSON.

